a) Block rotor test alone. b) Running-light and blocked-rotor and stator-resistance tests c) Both running-light and blocked-rotor tests d) Running-light test alone Ans: (b)
a) Dc shunt motor b) Dc series motor c) Induction motor d) Synchronous motor Ans: (a)
a) Stator flux remains constant b) Its torque exactly equals the mechanical load c) Its supply voltage remains constant d) Torque developed by it remains constant Ans: (b)
a) Decreases b) Increases c) Remains the same d) None of these Ans: (b)
a) Width of pole pitch b) Number of poles c) Supply frequency d) Any of the above Ans: (a)
a) To provide ventilation to the armature b) To protect the whole machine c) To hole the armature stampings/stator d) As a return path for the flux Ans: (d)
a) Locked rotor current is reduced b) Torque developed is increased c) Magnetizing current is decreased d) Both (a) and (b) Ans: (d)
a) More operating slip b) Lass starting torque c) More pull-out torque d) More starting torque Ans: (b)
a) Overload b) Low voltage c) High voltage d) Amu pf the above Ans: (d)
a) Reluctance motor b) Hysteresis motor c) Universal motor d) Shaded pole motor Ans: (b)